RECONSTITUTION OF METACHRONAL WAVES IN CILIATED CORTICAL SHEETS OF PARAMECIUM .1. WAVE STABILITIES

We reconstituted metachronal waves on ciliated cortical sheets prepare d from detergent-extracted Paramecium multimicronucleatum cells. Cilia ry movements of the cortical sheet, whose intracellular side adhered t o a glass coverslip, were reactivated by perfusion of a basic reactiva tion medium containing ATP. In this condition, the ciliary field showe d only unstable localised ripples. Addition of either cyclic AMP or cy clic GMP to the basic reactivation medium generated propagating metach ronal waves characteristic of each nucleotide. In order to estimate th e stability of the metachronal waves, autocorrelation coefficients wer e calculated from images of an 8 mu m diameter region within the react ivated ciliary field. The decay time for the correlation coefficient t o decrease to 0.5 was only 0.04 s in the basic reactivation medium, bu t was increased to 0.4 or 0.9 s by the addition of cyclic AMP or cycli c GMP, respectively. The decay time was dependent not only on the conc entration of cyclic nucleotide but also on the wave frequency. In orde r to test whether cyclic-nucleotide-dependent phosphorylation affected the generation of waves, the ciliated cortical sheets were thiophosph orylated by incubation in ATP-gamma-S (adenosine-5'-o-3-thiotriphospha te) medium containing either cyclic AMP or cyclic GMP. Following this, perfusion with the basic reactivation medium generated metachronal wa ves only after cyclic GMP treatment. The effect of cyclic GMP is proba bly related to phosphorylation of ciliary proteins.